I think that this has nothing to do with chunked holding disk files
(which are completely different from split files on tape).

Rather, you have datestamps (8 digits) in your headers, but timestamps
(14 digits) in your holding-disk directory names.

What version of Amanda are you using?  What is the value of the config
parameter "usetimestamps"?

Dustin

-- 
Storage Software Engineer
http://www.zmanda.com